SendKeys turns off NumLock

[twinnyfo]

OK Race fans, here's a whacky one:

In a separate module, I have these declarations:

Option Compare Database
Option Explicit
 
Public Declare Function GetTickCount Lib "kernel32" () As Long
Public Declare Function GetLastInputInfo Lib "user32" (pLII As Any) As Long
 
Private Type LastInputInformation
    cbSize As Long
    dwTime As Long
End Type
 
Public Function GetUsersIdleTime() As Long
    Dim LII As LastInputInformation
    LII.cbSize = Len(LII)
    Call GetLastInputInfo(LII)
    GetUsersIdleTime = FormatNumber((GetTickCount() - LII.dwTime) / 1000, 2)
End Function
 

These allow me to check whether someone has been using their machine and how long the system has been idle.

In the Timer Event of a form, set to 60,000 (60 seconds), I have this code:

Private Sub Form_Timer()
On Error GoTo EH
    If GetUsersIdleTime() >= 59 Then
        SendKeys "^"
    End If
    Exit Sub
EH:
    MsgBox "There was an error with the Timer!  Please contact your Database Administrator.", vbCritical, "Error!"
    Exit Sub
End Sub
 

What this does, and it works rather well, is it checks to see if the user has been active on the computer within the last 59 seconds. If not, it "types" a keystroke, in this case, it simulates hitting and releasing the Ctrl-Key. This prevents our screen savers from activating, thus breaking our network connections with the database. Our users will often have to review documents while the DB sits idle. This saves a lot of headaches, and some of you may be familiar with some of my recent posts conerning this.

Here is the issue: When I open this form, when the SendKeys statement activates, the NumLock status automatically turns OFF (it never turns itself back on, but must be turned on manually). This is a real pain, because this form uses the SSN of a person to search, so we often don't realize the NumLock is off until after we start keying in the number. (I have also simulated the Shift Key--"+" with similar results).

This is not a huge deal, but it is really annoying. This is the only thing that has changed on our machines, and it MUST be the form, because when I've opened the form and just let it sit, the NumLock turns off at exactly 60 seconds! (although not all the time--even stranger!)

Any thoughts or ideas on why this is happening and a way to prevent it from happening? Perhaps checking and resetting NumLock status--which I don't know how to do....

I am open to any ideas.

Thanks!

[neelsfer]

Maybe this will help if i am not missing the plot here.. I have the following code in a module, and call it with numon

Option Compare Database
 
Private Declare Sub keybd_event Lib "user32" ( _
ByVal bVk As Byte, _
ByVal bScan As Byte, _
ByVal dwFlags As Long, _
ByVal dwExtraInfo As Long)
Private Const VK_NUMLOCK = &H90
Private Const KEYEVENTF_KEYUP = &H2
Declare Function GetKeyState Lib "user32.dll" ( _
ByVal nVirtKey As Long) As Integer
 
Sub numon()
     'NUM_Off
    NUM_On
End Sub
 
Sub NUM_TOGGLE()
     'Toggle NUM-Lock key state
    keybd_event VK_NUMLOCK, 1, 0, 0
    keybd_event VK_NUMLOCK, 1, KEYEVENTF_KEYUP, 0
End Sub
 
Sub NUM_On() 'Turn NUM-Lock on
    If Not (GetKeyState(vbKeyNumlock) = 1) Then
        keybd_event VK_NUMLOCK, 1, 0, 0
        keybd_event VK_NUMLOCK, 1, KEYEVENTF_KEYUP, 0
    End If
End Sub
 
Sub NUM_Off() 'Turn NUM-Lock off
    If (GetKeyState(vbKeyNumlock) = 1) Then
        keybd_event VK_NUMLOCK, 1, 0, 0
        keybd_event VK_NUMLOCK, 1, KEYEVENTF_KEYUP, 0
    End If
 
End Sub

[twinnyfo]

neels,

Thanks for the code.... I will give it a try and see how it works!

[twinnyfo]

Neels,

Took a few very minor tweaks to add this code to a public module, then I reset the idle time, and use your code to make sure the NumLock is currently on. Success!

Thanks much!

[neelsfer]

Glad i could help somebody, after having received so much help on this site!